The phrasing of the subtitle is exact: a memoir in blindness, not of blind- ness. Like a portrait in oils — blindness being not just the subject, but the stuff of which this painfully stumbling, uncertainly reaching book is made. And not of, because it’s not something looked back on, like the memoir of a childhood: the blindness is still there waiting. ‘In’ acknowledges that, the way those even decades in recovery say ‘I am an alcoholic.’ And that, of course, heartbreakingly, is there too.

In 2006 the novelist Candia McWilliam started to lose her sight, and to lose it in an unusual and tormenting way. She suffers from something called blepharospasm, a disease where the muscles that hold her eyelids open malfunction. Her eyes worked fine, but she couldn’t see. For anyone, this would be horrible, but it is a particular torture for someone for whom books and reading mean near to everything.

Then there’s the rest: her mother’s suicide when she was a child; her dreadful descent into alcoholism; her stalled literary career; a grand mal seizure; falls and a hideously broken leg; abscess; drug-bloat; an agonising operation; circling thoughts of suicide; a howling sense of having no place in the world. By the time her cat is run over near the end, you wonder whether the God in whom McWilliam believes is having a laugh with her.

It’s hard to express how grim, almost bludgeoning, this book can be to read: how raw and how full of sadness. It’s not a misery memoir, with the invariable redemptive uplift at the end; it is a memoir in misery, written with a 12-stepper’s punishing clarity. ‘In an age of self-help books,’ she writes deadpan, ‘here is an account, to warn any reader, of almost exemplary self-unhelp.’

More immiserating than the blindness is McWilliam’s sense of waste and regret. She left her second marriage, to the academic Fram Dinshaw, and spent a decade in drink before recovering (her account of her drying-out clinic is almost chirpy). Though they are still married, he now lives with another woman, Claudia. Candia loves Claudia — she sketches her as pragmatic, tough and kind — but admits to poisonous jealousy. Leaving Fram, she believes, was the mistake that irrevocably crocked her life, and his continued cool friendship both sustains and pains her. She sees herself, in someone else’s phrase, as being his widow, but in the unusual circumstance that he is still alive.

She is loved, by her three children and two husbands as well as both their new partners, but she feels herself unlovable, a nuisance and a burden. And she feels — plainly, and piercingly — ugly. You could go through this manuscript to search-and-replace the word ‘fat’ with the word ‘self-hating’ — you’d find dozens, if not hundreds, of instances. Even when she was thin — in her twenties, working at Vogue — she saw herself as ‘a fat pigtailed child lost in books’.

This is the memoir of a woman who has not just suffered misfortune, but who also finds in herself a special gift for unhappiness, and is determined to analyse it minutely, to pick at knots of self-pity and passive-aggression.

But it is also the document of a writer, and a highly sensitive reading writer. McWilliam describes with discrimination and devoted care the writers she admires, and whose words help her navigate in the dark. She herself has a relationship with words that verges on the synaesthetic. They nugget in her mind: the word ‘epilimnion’ preoccupies her (it means the water below the surface of a lake) and runs for no other reason through a longish chunk of her story. Her first instinct for ‘dovecote’ is ‘columbarium’: she checks herself, writes ‘dovecote’, and notes that ‘Scots say doocoot, and so do I’.

Her style is eccentric; loopy, even. I don’t mean that in a pejorative sense. I mean it loops — backwards and forwards in time, in and out of the present tense, down skeins of association and figuration. If the reader feels like he’s in the oceanic jumble of someone else’s consciousness, that’s because he is:

I’m scared I’ve become like an inventory for the sale of an old dead person’s house, what the Scots call a displenishing; here I am, picking up lost bits and pieces of my scattered life to try to make something whole by putting it all together, my own flotsam and jetsam.

At times it rambles and drifts, at others it comes to crystalline exactness. From her childhood, here, she describes cannonballs stacked by a castle on the Ayrshire coast:

The balls were arranged in neat pyramids beside each gun. In the evening after a sunny day they held warmth until the light had gone and if you licked them the rusty salt taste was delicious. It’s the taste of oysters. Blood, iron, iodine.

The structure of the book is eccentric, too. The first half is in the shape of a pair of glasses: no joke. The first chapter is called Earpiece I, and a run of chapters follow the first lens, then the bridge, then the second lens, before we arrive at Earpiece II. The first lens was written; the second dictated, as McWilliam’s condition worsened.

The second half of the book is a consolidation — written a year later, in two months of intense work (not less than eight hours a day writing, was her idea) in isolation on the Hebridean island of Colonsay. Colonsay is restorative — a place associated with happiness in the form of one of the surrogate families into whose orbit, as a lonely child, she fell.

She describes the approach of a potentially curative operation (tendons from her knees were attached to her eyelids), its provisional success, and her movement towards being able to see and being able to think, too, about the possibility of making a life around her work:

The intention behind flying so low and close over my experience of the past year, since finishing my short overview of my life and subsequently boiling dry . . . has been to try to trace the old worn places where there has been life and to find the sources of things, to dam and retain the sweet and to drain the poisoned water, in order to begin again to write fiction.

I hope she does. This memoir feels sometimes almost too inward and private to be comfortably published. It shows agony partially alchemised into art — and a talent that, battered though its vessel is, hasn’t gone away. While we’re at it, let’s be glad the vessel made it too.

This article first appeared in the print edition of The Spectator magazine, dated August 7, 2010